It was also quite common for them to assassinate their emperors, to engage in civil war, to debase their currency so as to pay soldiers more, to hire barbarian

It was also quite common for them to assassinate their emperors, to engage in civil war, to debase their currency so as to pay soldiers more, to hire barbarian mercenaries, etc. It is one thing to acknowledge these things happened, it is quite another to argue these were economically rational actions in the best interest of Rome.